diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index 4b1304f..6ea791f 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -43,3 +43,25 @@ jobs:
         run: pnpm install
       - name: Lint JS files
         run: pnpm run lint
+  Typecheck:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+      - name: Restore node_modules cache
+        uses: actions/cache@v4
+        with:
+          path: node_modules
+          key: ${{ runner.os }}-node-modules-${{ hashFiles('package.json') }}
+          restore-keys: |
+            ${{ runner.os }}-node-modules
+      - name: Install pnpm
+        uses: pnpm/action-setup@v4
+      - name: Install dependencies
+        run: pnpm install
+      - name: Typecheck files
+        run: pnpm run typecheck
diff --git a/package.json b/package.json
index baf0439..dbea021 100644
--- a/package.json
+++ b/package.json
@@ -23,17 +23,15 @@
   "files": [
     "dist"
   ],
-  "dependencies": {
-    "@ungap/structured-clone": "^1.0.1"
-  },
   "devDependencies": {
     "prettier": "^3.3.3",
     "vite": "^6.3.5",
     "vitest": "^3.2.4"
   },
   "scripts": {
-    "build": "vite build",
-    "lint": "prettier --check 'src/**/*.js'",
+    "typecheck": "tsc --noEmit",
+    "build": "vite build && tsc",
+    "lint": "prettier --check 'src/**/*'",
     "test": "vitest"
   },
   "packageManager": "pnpm@10.12.1"
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index b3b91ab..529d5f2 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -7,10 +7,6 @@ settings:
 importers:
 
   .:
-    dependencies:
-      '@ungap/structured-clone':
-        specifier: ^1.0.1
-        version: 1.3.0
     devDependencies:
       prettier:
         specifier: ^3.3.3
@@ -292,9 +288,6 @@ packages:
   '@types/node@24.0.3':
     resolution: {integrity: sha512-R4I/kzCYAdRLzfiCabn9hxWfbuHS573x+r0dJMkkzThEa7pbrcDWK+9zu3e7aBOouf+rQAciqPFMnxwr0aWgKg==}
 
-  '@ungap/structured-clone@1.3.0':
-    resolution: {integrity: sha512-WmoN8qaIAo7WTYWbAZuG8PYEhn5fkz7dZrqTBZ7dtt//lL2Gwms1IcnQ5yHqjDfX8Ft5j4YzDM23f87zBfDe9g==}
-
   '@vitest/expect@3.2.4':
     resolution: {integrity: sha512-Io0yyORnB6sikFlt8QW5K7slY4OjqNX9jmJQ02QDda8lyM6B5oNgVWoSoKPac8/kgnCUzuHQKrSLtu/uOqqrig==}
 
@@ -699,8 +692,6 @@ snapshots:
       undici-types: 7.8.0
     optional: true
 
-  '@ungap/structured-clone@1.3.0': {}
-
   '@vitest/expect@3.2.4':
     dependencies:
       '@types/chai': 5.2.2
diff --git a/src/__tests__/alchemyApiDeserializer.spec.js b/src/__tests__/alchemyApiDeserializer.spec.ts
similarity index 99%
rename from src/__tests__/alchemyApiDeserializer.spec.js
rename to src/__tests__/alchemyApiDeserializer.spec.ts
index 7674dd7..f922a62 100644
--- a/src/__tests__/alchemyApiDeserializer.spec.js
+++ b/src/__tests__/alchemyApiDeserializer.spec.ts
@@ -1,4 +1,5 @@
 import { deserializePage, deserializePages } from "../alchemyApiDeserializer"
+import { describe, expect, it } from "vitest"
 
 describe("deserializePage", () => {
   it("does not return any deprecated elements for single page", () => {
diff --git a/src/__tests__/deserialize.spec.js b/src/__tests__/deserialize.spec.ts
similarity index 95%
rename from src/__tests__/deserialize.spec.js
rename to src/__tests__/deserialize.spec.ts
index cb8c3fc..d36c8a1 100644
--- a/src/__tests__/deserialize.spec.js
+++ b/src/__tests__/deserialize.spec.ts
@@ -1,4 +1,5 @@
 import { deserialize } from "../deserialize"
+import { describe, expect, it } from "vitest"
 
 describe("deserialize", () => {
   it("Complex serialize", () => {
diff --git a/src/alchemyApiDeserializer.js b/src/alchemyApiDeserializer.ts
similarity index 74%
rename from src/alchemyApiDeserializer.js
rename to src/alchemyApiDeserializer.ts
index f87db13..c70d505 100644
--- a/src/alchemyApiDeserializer.js
+++ b/src/alchemyApiDeserializer.ts
@@ -1,10 +1,10 @@
 import { deserialize } from "./deserialize"
 
 // Recursively filters all deprecated elements and essences from collection
-function filterDeprecatedElements(elements) {
-  const els = []
+function filterDeprecatedElements(elements: any) {
+  const els: any = []
 
-  elements.forEach((element) => {
+  elements.forEach((element: any) => {
     if (element.nested_elements?.length > 0) {
       element.nested_elements = filterDeprecatedElements(
         element.nested_elements
@@ -14,7 +14,7 @@ function filterDeprecatedElements(elements) {
       element.nestedElements = filterDeprecatedElements(element.nestedElements)
     }
     if (element.essences?.length > 0) {
-      element.essences = element.essences.filter((essence) => {
+      element.essences = element.essences.filter((essence: any) => {
         return !essence.deprecated
       })
     }
@@ -27,16 +27,16 @@ function filterDeprecatedElements(elements) {
 }
 
 // Returns deserialized page without deprecated content
-export function deserializePage(pageData) {
+export function deserializePage(pageData: any) {
   const page = deserialize(pageData)
   page.elements = filterDeprecatedElements(page.elements)
   return page
 }
 
 // Returns deserialized pages without deprecated content
-export function deserializePages(pagesData) {
+export function deserializePages(pagesData: any) {
   const pages = deserialize(pagesData)
-  pages.forEach((page) => {
+  pages.forEach((page: any) => {
     page.elements = filterDeprecatedElements(page.elements)
   })
   return pages
diff --git a/src/deserialize.js b/src/deserialize.ts
similarity index 80%
rename from src/deserialize.js
rename to src/deserialize.ts
index a1edacc..20f6d2b 100644
--- a/src/deserialize.js
+++ b/src/deserialize.ts
@@ -1,6 +1,4 @@
-import structuredClone from "@ungap/structured-clone"
-
-export function deserialize(originalResponse, options = {}) {
+export function deserialize(originalResponse: any, options = {}) {
   const response = structuredClone(originalResponse)
   if (!options) {
     options = {}
@@ -9,7 +7,7 @@ export function deserialize(originalResponse, options = {}) {
   const included = response.included || []
 
   if (Array.isArray(response.data)) {
-    return response.data.map((data) => {
+    return response.data.map((data: any) => {
       return parseJsonApiSimpleResourceData(data, included, false, options)
     })
   } else {
@@ -22,7 +20,12 @@ export function deserialize(originalResponse, options = {}) {
   }
 }
 
-function parseJsonApiSimpleResourceData(data, included, useCache, options) {
+function parseJsonApiSimpleResourceData(
+  data: any,
+  included: any,
+  useCache: any,
+  options: any
+) {
   if (!included.cached) {
     included.cached = {}
   }
@@ -47,9 +50,9 @@ function parseJsonApiSimpleResourceData(data, included, useCache, options) {
       const relationRef = data.relationships[relationName]
 
       if (Array.isArray(relationRef.data)) {
-        const items = []
+        const items: any = []
 
-        relationRef.data.forEach((relationData) => {
+        relationRef.data.forEach((relationData: any) => {
           const item = findJsonApiIncluded(
             included,
             relationData.type,
@@ -77,10 +80,10 @@ function parseJsonApiSimpleResourceData(data, included, useCache, options) {
   return resource
 }
 
-function findJsonApiIncluded(included, type, id, options) {
+function findJsonApiIncluded(included: any, type: any, id: any, options: any) {
   let found = null
 
-  included.forEach((item) => {
+  included.forEach((item: any) => {
     if (item.type === type && item.id === id) {
       found = parseJsonApiSimpleResourceData(item, included, true, options)
     }
diff --git a/src/main.js b/src/main.js
deleted file mode 100644
index 3ed4a63..0000000
--- a/src/main.js
+++ /dev/null
@@ -1,2 +0,0 @@
-export * from "./alchemyApiDeserializer.js"
-export * from "./deserialize.js"
diff --git a/src/main.ts b/src/main.ts
new file mode 100644
index 0000000..4833862
--- /dev/null
+++ b/src/main.ts
@@ -0,0 +1,2 @@
+export * from "./alchemyApiDeserializer"
+export * from "./deserialize"
diff --git a/tsconfig.json b/tsconfig.json
new file mode 100644
index 0000000..bc4b739
--- /dev/null
+++ b/tsconfig.json
@@ -0,0 +1,12 @@
+{
+  "compilerOptions": {
+    "strict": true,
+    "outDir": "dist",
+    "removeComments": true,
+    "noImplicitAny": true,
+    "declaration": true,
+    "emitDeclarationOnly": true
+  },
+  "include": ["src/**/*"],
+  "exclude": ["src/__tests__"]
+}
diff --git a/vite.config.ts b/vite.config.ts
index d678d95..10e9ee2 100644
--- a/vite.config.ts
+++ b/vite.config.ts
@@ -1,8 +1,6 @@
 import { defineConfig } from "vite"
 import { resolve } from "path"
 
-const external = ["@ungap/structured-clone"]
-
 export default defineConfig({
   build: {
     lib: {
@@ -12,9 +10,6 @@ export default defineConfig({
       },
       formats: ["es"],
       fileName: (_format, entryName) => `${entryName}.js`
-    },
-    rollupOptions: {
-      external
     }
   }
 })
diff --git a/vitest.config.mjs b/vitest.config.mjs
index ad3b8df..90f9f26 100644
--- a/vitest.config.mjs
+++ b/vitest.config.mjs
@@ -2,6 +2,6 @@ import { defineConfig } from "vitest/config"
 
 export default defineConfig({
   test: {
-    globals: true
+    globals: false
   }
 })